Andreas Sigismund Marggraf

Andreas Sigismund Marggraf (* March 3, 1709 in Berlin, † August 7, 1782 in Berlin) was a German chemist. He is considered the last important chemists of the era of the phlogiston theory and discovered the sugar content of native plants.

Life

Andreas Sigismund was the first son of Henning Christian Marggraf (1680-1754) and Anna Martha Kellner ( 1685-1752 ). His father, founder and owner of the Bears pharmacy, the young people taught in pharmacy and chemistry. Later he was a student of chemistry students of Professor Caspar Neumann, the head of the class practical (pharmaceutical ) chemistry at the Collegium Medico - chirurgicum in Berlin. Neumann, a student of Georg Ernst Stahl, Marggraf introduced the phlogiston theory, which should determine its chemical thinking throughout his life. To deepen his knowledge Marggraf studied in Strasbourg chemistry and physics, in Hall medicine and in Freiberg metallurgy. Before he returned to Berlin in 1735, he attended a few huts and mining sites in order to enhance his knowledge.

Back in Berlin, Marggraf worked until 1752 in his father's pharmacy the Golden Bears. In 1738 he became a member of the Royal Prussian Academy of Sciences. 1754 He introduced pure alumina dar. From 1754 he was able to fully concentrate on its chemical research because it has been supplied by the Academy is a laboratory, a service apartment ( Dorotheenstr. 10 ) are available. Due to his discovery of sugar in the beet ( 1747 ) he became in 1760 director of the Physico- Mathematical classes at the Royal Academy of Sciences, a service position, which he held until his death in 1782 after the death of the current Director, Johann Theodor Eller.

His laboratory and his official residence were taken over by his successor, the Physical - Mathematical Franz Carl Achard class.

Marggraf held his current term chemical issues remotely and devoted himself mostly his analytical investigations in the laboratory, a behavior that is paired with its investigation successes earned him a lot of credit.

Among his students was Martin Heinrich Klaproth belonged.

Services

• Improved method for phosphorus recovery by " distillation " of eingedampftem urine with Bleioxichlorid ( horn lead), sand and coal ( 1743). Marggraf realized that phosphorus increases during the combustion of weight (see Antoine Lavoisier ). The phosphoric acid and salts of phosphoric acid (sodium ammonium phosphate = Sal microcosmicum ) he examined thoroughly.
• Production of potassium cyanide from bovine blood and use of the formation of Prussian blue for iron detection, description of the dissolving action of potassium cyanide on metal salts and precious metals ( silver, gold ) ( 1745)
• Recovery of zinc by reducing calamine with charcoal powder absence of air ( 1746 ) and by heating zinc sulphate, which he obtained from calamine and alum
• Investigations of the sugar content of native plants. With determination of a high sugar content of the beet he lays the foundation for a domestic sugar industry ( beet sugar industry). In 1747 he contributed his observations before the Academy: " So I came occasionally to the idea, even the parts of various plants, which have a sweet taste to explore and after manifold trials, which I have made, I found that some of these plants, not just a sugar -like substance, but in fact, contain real sugar, which exactly resembles the well-known derived from sugar cane. " He now mentioned three particularly easy growing, gedeihener on mediocre soil plants from their roots, he has pure sugar isolated: 1) the white Mangold ( cicla officinarum ), 2) the sugar root ( Sisarum Dodonaci ), 3) the beet - chard, the beet or red chard. The extraction of the sugar from the juice of roots and the purification thereof he describes in detail, but there it stops. The final and essential step, the recovery of these experiments to a local sugar industry, he leaves his friend, pupil and successor Franz Karl Achard, although he himself completely the significance of his discovery recognizes, as is clear from his own words: " Based on the above here Try it is clear that this sweet salt can be prepared just in our home as in the regions where the sugar cane grows. " from: General German Biography
• Introduction of the microscope as an investigative tool in chemistry. Marggraf used it for monitoring of sugar crystals. ( 1747 )
• He studied in Berlin the water of a ferruginous spring 1748. Since he confirmed the water healing powers, today the district was given the name " Healthy fountain" ( hamlet in the district Berlin -Mitte).
• Extraction of formic acid by distillation of ants ( 1749)
• Differentiation of formic and acetic acid by formic acid reduction of the mercury oxide
• Distinction of sodium and potassium by flame coloration ( 1758)
• Richard Watson ( 1750) discovered the new metal platinum, it was investigated in detail by H. Th Scheffler in Upsala. Also Marggraf examined the metal with aqua regia and received a platinum chloride solution, this solution was used for the separation of sodium from the potassium salts.
• First characterizations of the inorganic color pigment ultramarine ( 1768).

Works

• Most treatises Marggraf found in the Mémoires de l' Académie des Sciences de Berlin from 1747-1779 and in the Miscellanea Berolinensia.
• Chemical writings, Berlin 1761 and 1767th